According to Aztec Tradition, They Wandered Across What Is Today

According to Aztec tradition, they wandered across what is today Mexico until they came to an island with an eagle standing on a cactus with a snake in its mouth. According to their prophecy, this would be their new home. The Aztecs established their capital city on an island in Lake Texcoco, where tradition said they found the eagle. This demonstrates the concept of a(n) :

A) tall tale.
B) origin myth.
C) folk tale.
D) fairy tale.
E) ethnohistory.